Propeller blade reshaping machine



April 24, 1956 F. DOBBS 2,742,947

PROPELLER BLADE RESHAPING MACHINE Filed NOV. 10, 1952 2 Sheets-Sheet 1 U f I) INVENTOR.

Fred Dob bs ATTYS.

April 24, 1956 F. D0555 2,742,947

PROPELLER BLADE RESHAPING MACHINE 2 Sheets-Sheet 2 Filed Nov. 10, 1952 lllllh Fig. 2 5a 60 -o i,- o as I v 64 o e7 e7. 69 g o I 2 lg. 3

, I 56 J 3 57 2 r9 ml +5 1 INVENTQR. 3 Fred Dobbs 33 H bV" ATTYS.

United States Patent 2,742,947 PROPELLER BLADE RESHAPING MACHINE Fred Dobbs, Seattle, Wash. Application November 10, 1952, Serial No. 319,709

8 Claims. (Cl. 153-78) The present invention relates to a machine for reshaping the blades of ship propellers which have become deformed .as from impact with logs and other debris.

In the prior art ship propellers were reconditioned by manually sledging the blades, and when it is realized that these propellers are several feet across, it can readily be objects and advantages in view, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Figure 1 is a perspective view of my machine as viewed from the front and with a propeller mounted thereon ready for the reshaping of one of its blades.

Fig. 2 is a side perspective view of the machine and propeller.

Fig. 3 is a vertical sectional view taken along line 3-3 of Fig. 2; and

Fig. 4 is a vertical sectional view taken along line 4-4 of Fig. 3.

I Referring to the drawings it is seen that a rigid table is provided which is supported at the corners by legs 11. The feet of the front and rear pairs of legs are connected by laterally extending plates 12, 13 and these are in turn cross-connected by longitudinal frame members 14, 15. Held by bolts 16 to the table are two pairs of corner brackets 17-17 and 18-18 extending laterally beyond the sides of the table and each presenting opposed grooves with concavely curved seats facing fore and aft. Guided in these grooves are tongues 20, 21 provided at the ends of each of a pair of beams 22, 23 extending along the longitudinal sides of the table in spaced relation thereto. The tongues have a gentle convex curve which mates with the concave seats of the grooves, the curvatures being such that the beams can pivot about either end.

Movement of the beams 22, 23 is accomplished by the use of four double-acting piston units 24, distinguished along with their control systems by the use of the letters A to D. Each of these beams is secured top and bottom to a respective leg 11 by pairs of bolts 25. The piston rods 26 of the piston units have head blocks 27 positioned in recesses at the underside of the beams. Each of these head blocks is interconnected by a respective pair of links 30, 31 located at each side of the beam and pivotally connected to the latter by a pin 32 and to the head block by a pin 33. These links permit the ends of the beams to be raised independently of one another by the piston units. l

The piston units are controlled by four control valves 34 located at the front of the table. These units have upstanding control handles 42 pivoted at their lower ends and each unit is connected at its underside to a supply header 35 fed from a pump 36 obtaining its supply from a sump 37. As viewed in Fig. 1 each of the control valves dumps from its right side into a discharge header 38 leading back to the sump. Coming from the left side of each control valve is'a respective pair of lines 40, 41, one extending to the lower end of the piston unit to which the control valve is connected and the other leading to the upper end. Accordingly, for purposes of example, when the handle 42A is pulled forwardly pressurized fluid flows from the supply header 35 through the control valve 34A and via the line 40A to the underside of the piston of the piston unit 24A. Atthe same time fluid in the upper end of the piston chamber dumps through the line 41A and control valve into the discharge header 38. As a result the forward end of the beam 22 is raised. Conversely, when the handle 42A is pushed rearwardly, pressurized fluid flows through the line 41A to cause the piston to move downwardly and the fluid at the lower end of the piston chamber is forced out through the line 40A. When the handle is in a neutral position the controlled piston remains at a status quo. Operation of the pump 36 is controlled by a lever 43 connected with the pump by a suitable linkage.

Toward the rear end of the table there is provided an elongated anchoring bolt 44 which is threadably received through a circular mounting bed 45 surmounted by an interfitting plate 46 and is locked with respect to the table by a nut 47 located therebeneath. The center portion of the bolt is unthreaded and its upper end portion 48 is reduced in diameter and threaded to receive a hold-down nut 50 tightened by a wrench 51. The opening through the plate 46 may be tapered so that when the propeller to be reconditioned is lowered thereon, the propeller hub extends slightly into the tapered opening and hence is automatically centered. Spacers 52 are used to fill in between the threaded portion 48 and the propeller so that pressure can be applied by the hold-down nut. The extreme upper end of the anchoring bolt may be further reduced to receive a pitchometer 53 for checking the pitch of the propeller blades.

Guided on the beams 22, 23 are a pair of slotted slide members 54, 55 which are apertured at their upper ends for receiving pins 56, 57 which serve as fulcrums for two pairs of upstanding arms 5858 and 60-60. These arms have multiple holes 61 along their length to give a plurality of possible positions for pins 62, 63 passing through the ends of a bending bar-64 extending crosswise above the table. This bar is longitudinally slotted with the slot, denoted 65, being of a width and length suflicient to receive the tip end portion of the blades of the largest propeller to be reconditioned. An eye 66 is provided at the upper side of the bar for receiving the hook of a chain hoist so that the bar and the arms 58, 60 can be raised slightly with respect to the beams 22, 23, this being permitted by way of the fact that the length of the slots 61 in the slide members 54, 55 exceeds the width of the beams as shown in Fig. 3. When this is done,-the bending bar and the arms can be readily moved along the beams 22, 23 to bring the tip end portion of a blade 66 of a propeller, mounted as aforedescribed, within the slot as shown in the drawings. In this regard it bar to transfer bending forces from the bar and through the blocks 67, 63 to the propeller blade can be very accurately controlled. If a substantial movement of an end of the bar is required then the underlying beam 22 or 23 is moved bodily by energizing the piston units at the ends thereof. For example, if the handles 42A and 42B are pushed rearwardly the beam 22 will be lifted uniformly throughout its length. By way of comparison if it is desired to lower the higher end of the bending bar a slight amount as viewed in Fig. 1 such can be accomplished by lowering either of the ends of the beam 22 through the act of pushing the handles 42A and 428. The amount of vertical movement of the end of the bending bar in such a case will, of course, be proportioned to the distance of the slide member 54 from the pin 32 about which the beam 22 is pivoted.

From the above description it can be seen that an infinite variety of bending actions can be performed on a propeller blade by varying the positions, shapes, and

sizes of the wedging blocks and the positions and movements of the ends of the bending bars. The bending is done in steps, a little at a time, and the bend resulting from each step is set by two or three blows from a sledge hammer applied inwardly somewhat of the application of the bending forces before the latter are released. This prevents the blade from springing back into its deformed shape.

It is thought that the invention, and its advantages, will have been clearly understood from the foregoing detailed description of the preferred illustrated embodiments. It is self-evident that changes from the illustrated and described embodiments may be resorted to Without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation to which the employed language admits.

What I claim is:

1. ln a propeller blade reshaping machine, a pair of parallel laterally spaced beams pivotally mounted at one end for swinging movement in parallel vertical planes, 3. pair of upstanding arms carried by the beams and mounted for swinging movement in a generally vertical plane toward and away from each other, a bending bar pivotally connected at its ends to the said arms and formed with an elongated opening therethrough facing fore and aft with respect to the said beams for receiving a propeller blade, and means for selectively swinging the beams independently or in unison about their said pivotally mounted ends.

2. In a propeller blade reshaping machine, a pair of parallel laterally spaced beams each pivotally mounted at both of its ends for swinging movement in parallel vertical planes, a pair of upstanding arms carried by the beams for swinging movement in a generally vertical plane toward and away from each other, a bending bar pivotally connected at its ends to the said arms and formed with an elongated opening therethrough facing fore and aft with respect to the said beams for receiving a propeller blade, and means for selectively swinging the beams independently or in unison about their ends or for bodily moving the blades in unison or separately in a vertical direction.

3. In a propeller blade reshaping machine, a pair of parallel laterally spaced beams, doubleacting piston units mounted beneath the ends of the beams, links pivotally interconnecting the ends of the beams with the underlying piston units so that the ends of each beam can be raised independently of one another by the respective piston units, a pair of upstanding arms carried by the beams and mounted for swinging movement in a generally vertical plane toward and away from each other, and a bending bar pivotally connected at its ends to the said arms and formed with an elongated opening therethrough facing fore and aft for receiving a propeller blade.

4. In a propeller blade reshaping machine, a pair of parallel laterally spaced beams, double-acting piston units mounted beneath the ends of the beams, links pivotally interconnecting the ends of the beams with the underlying piston units so that the ends of each beam can be raised independently of one another by the respective piston units, a pair of guides slidably mounted on the beams, a pair of upstanding arms pivotally connected at their lower ends to the said guides for swinging movement in a generally vertical plane toward and away from each other, and a bending bar pivotally connected at its ends to the said arms and formed with an elongated opening therethrough facing fore and aft for receiving a propeller blade.

5. In a propeller blade reshaping machine, a table having a pair of spaced laterally extending brackets at each of its lateral sides, means for securing a propeller on the table with its rotary axis vertical and a blade extending fore and aft, 2. pair of beams at opposite sides of the table and with their ends having an arcuate tongueand-groove interfit with the said brackets permitting the beams to be pivoted about either end, double'acting piston units beneath the ends of the beams, links pivotally interconnecting the pistons and the beams, a pair of guides slidably mounted on the beams, 21 pair of upstanding arms pivotally connected at their lower ends to the said guides for swinging movement in a generally vertical plane toward and away from each other, and a bending bar pivotally connected at its ends to the said arms and formed with an elongated opening therethrough facing fore and aft for receiving the said propeller blade.

6. The structure of claim 5 wherein means are provided for selectively raising or lowering the pivotal connections between the ends of the bending bar and the upstanding arms so that the elongated opening in the bending bar can be sloped at will with respect to the table.

7. In a propeller blade reshaping machine, a pair of laterally spaced beams pivotally mounted at one end for swinging movement, anchoring means between said beams for holding a propeller stationary, a pair of arms carried by said beams and mounted for swinging movement toward and away from each other, bending means pivotally connected to the said arms and providing two opposed faces arranged to receive the blade of a propeller therebetween, and means operatively associated with the beams for swinging the beams about their said pivotally mounted ends to responsively move said opposed faces of the bending means with respect to said anchoring means.

8. In a propeller blade reshaping machine, a pair of laterally spaced beams, anchoring means between said beams for holding a propeller stationary, a pair of guides slidably mounted on said beams, a pair of arms carried by said guides and mounted for swinging movement toward and away from each other, bending means pivotally connected to the said arms and providing two opposed faces arranged to receive the blade of an anchored propeller therebetween, and means operatively associated with said beams for selectively moving the beams independently or in unison to responsively move said opposed faces of the bending means with respect to said anchoring means.

References Cited in the file of this patent UNITED STATES PATENTS 1,909,097 Damerell May 16, 1933 2,124,760 Burrington July 26, 1938 2,297,055 Grad Sept. 29, 1942 2,359,277 Saunders Oct. 3, 1944 2,611,414 Sampatacos Sept. 23, 1952 

